1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a display apparatus and a brightness adjusting method thereof, and more particularly, to adjusting a brightness of part and all of an image of an input video signal.
2. Description of the Related Art
In general, a display apparatus such as a liquid crystal display (LCD) is used to display a video on a television, a notebook computer, and a desktop computer. Since the LCD cannot produce a light by itself, it displays an image using a light emitted from a separate light source. Thus, the LCD has a display panel and a luminous element comprising a backlight at the rear side of the display panel. The display panel adjusts the transmittance of the light emitted from the luminous element to thus display the image.
In the related art, a uniform backlight for uniformly illuminating the entire display panel has been used in the luminescence part of the LCD. The uniform backlight displays both the dark image and the bright image with the light of the same luminance. While an image showing a firework scene or an explosion scene partially requires a relatively high luminance, it is hard to represent the vivid image because of the lack of proper compensation.
In addition, since the light emitted from the uniform backlight comes into the display panel and causes interference, the LCD cannot display the black image of the pixel value ‘0’ as a true black image and accordingly the contrast ratio of the entire screen decreases. Even in the dark image displayable through light of low luminance, the light of the same luminance is produced from the uniform backlight thus wasting power.